1998/11/29 by A. J. Castro-Tirado, M. R. Zapatero-Osorio, J. Gorosabel +23 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Gamma-ray bursts and supernovae #Scientific Research and Discoveries #astro-ph
paper · pdf · doi:10.1086/311846
published as Astrophys.J. 511 (1999) L85-L88 · Accepted for publication in Astrophysical Journal Letters
arxiv created 1998/11/29 · openalex publication_date 1999/02/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We imaged the X-ray error box of GRB 980703, beginning 22.5 hr after the γ-ray event, in both the optical R and near-infrared H bands. A fading optical/IR object was detected within the X-ray error box, coincident with the variable radio source reported by Frail et al. in 1998, who also detected the optical transient independently of us. Further imagery revealed the gamma-ray burst (GRB) host galaxy, with R = 22.49±0.04 and H =20.5 ± 0.25, the brightest so far detected. When excluding its contribution to the total flux, both the R - and H -band light curves are well fit by a power-law decay with index α≃1.4. Our data suggest an intrinsic column density in the host galaxy of ~3.5 × 10 21 cm -2 , which indicates the existence of a dense and gas-rich medium in which the GRB occurred, thus supporting the hypernova model scenarios.